1. Field of Invention
The present invention relates to a testing method for liquid crystal display (LCD) panels. More particularly, the present invention relates to an improved testing method for LCD panels.
2. Description of Related Art
In the manufacturing process of LCD panels, many panels are formed simultaneously on a large substrate. After forming the panels, each panel is tested one by one to determine whether the function of each panel manufactured is normal. When the test is completed, the substrate is segmented into individual panels. FIG. 1 shows a layout of panels formed on a large glass substrate in the prior art. On the glass substrate 10 are four panels 12 having the same size. Each panel 12 has plural vertical source lines 14 and plural horizontal gate lines 16. The intersections of these source lines 14 and gate lines 16 constitute a pixel array of LCD 12.
Before segmenting the glass substrate 10 into individual panels 12, the panels 12 should be tested to determine whether each panel 12 functions normally. The test is performed by using a testing circuit that is the same size as the panel 12. The testing circuit comprises many probes, wherein the position of each probe respectively corresponds to each source pad 13 of the source lines 14 and each gate pad 15 of the gate lines 16. By contacting the probes of the testing circuit with the source pads 13 and the gate pads 15 of the panel, and then testing each source pad 13 or gate pad 15, whether each source line 14 or gate line 16 functions normally or not can be determined.
When the testing circuit completes the test on one panel 12, it moves to another panel 12 on the glass substrate 10 until all of the panels 12 are tested. FIG. 1 shows, for example, a glass substrate 10 comprising four panels 12. In this case, the testing circuit is moved to these four panels 12 by a robot arm to test each panel 12 one by one.
However, such a testing method is time-consuming since the testing circuit is moved to and positioned on each panel that needs to be tested. When the number of the panels on the substrate increases, the testing time increases. Furthermore, the testing time increases significantly when the panels on the substrate are of different sizes. This is because different-sized panels need to be tested by using correspondingly different-sized testing circuits. The testing circuit needs to be changed during the test, and thus the testing time increases.
FIG. 2 shows a layout of a glass substrate 20 comprising panels with different sizes. The glass substrate 20 comprises large-sized panels 22a and small-sized panels 22b. When conducting the test, one uses testing circuits sized correspondingly to those of panels 22a and panels 22b and test them separately. Changing the testing circuit results in an increase of the testing time. Moreover, if the substrate comprises several different-sized panels, testing circuits of various sizes are needed which raises the testing cost.
For the foregoing reasons, there is a need for an improved testing method for LCD panels to reduce the time for moving the testing circuit and thereby speed up the test on all the panels on the substrate. Further, there is a need for an improved testing method for LCD panels which can be applied to a substrate having various sizes of panels to reduce the overall testing time.